Saturday, October 10, 2009


At the last blog, I talked about the most common type of sudden cardiac death, those that we could not predict and so often cannot help. It is also important to note that there are some sudden cardiac death causes that can be treated if detected early. Some of them are due to heart muscle abnormalities like cardiomyopathies, some are due to electrical instability of the heart, and of course those that happen in patients with severe heart failure.
Every now and then we hear of athletes, lately some footballers who collapsed while playing professional soccer and also some American footballers. In those who had autopsy done, many of these sportsmen had hypertrophic cardiomyopathy as their cardiac disease causing sudden cardiac death. Hypertrophic cardiomyopathy is a condition whereby the heart muscle have become abnormally thickened, especially in the area around the outlet of the left ventricle. This will cause the blood flow out of the heart to be compromised, resulting in failure of the whole cardiovascular circulation and collapse. These patients are also associated with a higher possibility of electrical instability of the heart. Its so sad, because a good cardiac assessement before they are allowed to play would have detected the ondition, which is treatable. It is known in USA that some footballers are only assessed by GPs before they are signed on s professionals.
In the cardiac electrical instability group three varieties should be mentioned obviously because they are the most common of these uncommon causes. Some children ( sometimes they live to adulthood ) are grown with some abnormal conduction system, which makes the heart unstable and susceptible to VF. They are afew of these arrhythmias which the patients are born with. Some technical names include the "the long QT syndrome " and the "Brugada syndrome ". The first ( long QT syndrome ), maybe congenital, but can also be induced by drugs and also metabolic upsets. The second ( Brugada Syndrome ) is important to us because although it was first discovered in Spain, many sudden cardiac deaths among foreign workers in Singapore and the Philippines, may be due to the Brugada syndrome. There are obvious ECG signs and can be spotted. In that case, it can be treated and so sudden cardiac death avoided. We hav also seen sudden cardiac death in people who went on extreme fasting, which we think is dued to severe electrolyte imbalance and a hidden long QT syndrome. Most of these arrhythmic sudden cardiac deaths sometimes require them to survive the first episode, so that we can then treat them. Some of these patients with electrical instability can be treated with drugs and sometimes with implantable defibrilators.
The last group of people who collapse and die suddenly are patients with poor heart function and heart failure. It is now well known that the most common cause of death in patients with severe heart failure ( more specifically systolic heart failure ) is VF ( ventricular fibrillation ). When they are in mild or moderate heart failure, treatment of heart failure with drugs will greatly improve their quality of life, and some drugs would also improve their quantity of life ( not all drugs do this ). However, it is becoming more and more abvious to us that very often, our heart failure patients just collapse and die ( suden cardiac death ). In fact, the Americans are advocating that patients with severe heart pump failure should also get an automatic implantable cardiac defibrillator ( AICD ). This may prolong the quantity of life. This is however a very expensive therapy and is also slightly invasive and so not gain much popularity.
The automatic implantable cardiac defibrillator ( AICD ) is a defibrillator that is now condensed into a small implantable unit. It can be implanted through a small chest incision and is considered a relatively minor surgical procedure. It can automatically detect the VF when it comes on and then delivers a programmed shock that will convert the heart rhythm back to normal. It works like the external defibrillator that we and the St John Ambulance are advocating to be placed in popular public places for citizens to help defibrillate anyone who may suffer a sudden cardiac arrest in public. Because of the many functions that the AICD must do ( so that it does not shock wrongly ) the battery does not last so long and may have to be changed as often as 3-5 years, depending on how many times it is called to function.
I suppose the message that I wish to put across is that, there are many unfortunate people who may collapse in public, that we cannot help. But it is important to know that there are also some ( maybe the minority ) that we can, and we should. Regular checkups who those at risk of CAD would be a very good strategy to try and prevent the unfortunate sudden cardiac death.

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